The following is a tabulation of prior art that presently appears relevant:
Pat. No.Kind CodeIssue DatePatentee5,534,366B1Jul. 9, 1996Hwang et. Al.6,043,629B1Mar. 28, 2003Ashley et. Al.7,304,453B2Dec. 4, 2007Eaves et. Al8,330,420B2Dec. 11, 2012Kim et. Al 8,386,175B2Feb. 26, 2013Limbaugh, et. Al
Pending Patent ApplicationsPub DateApplicantUS 2008/0291623Nov. 27, 2008Genin et. AlUS 2009/0267799Oct. 29, 2009Laborde, GregoryUS 2010/0114512May 6, 2010Cotton et. AlUS 2014/0093760 A1Mar. 4, 2014Hermann, W.A.
The rapidly emerging small satellite markets, especially those that weigh less than a pound, and extending up into the 100 pound plus range, along with weight sensitive launch vehicles require the delivery of robust, safe and reliable power as their larger satellite and launch vehicle provider counterparts do. Unfortunately the large legacy battery chemistry systems such as silver-zinc, lead acid, nickel cadmium and lithium-ion deployed throughout the aerospace industry on missiles, rockets satellites and high altitude systems are not adaptable in architecture or design philosophy to accommodate these smaller size satellites or weight sensitive launch vehicles, and as a result, there is no safe, modular, scalable, expandable, deployable, employable, practical, radiation hardened and intelligent battery system available to efficiently power this new genre of satellites, weight sensitive launch vehicles, or other niche areas where similar operational requirements may exist. The greatest battery power density is achieved only when flat lithium polymer pouch cells are stacked flat upon each other such as widely utilized in the remote control model aircraft hobby industry and growing personal electronics industry, and as yet, there is no invention or deployment of a multiple flat cell lithium polymer battery system which is available or adaptable that can be consistently employed in the all-encompassing spectrum from a simple atmospheric pressure environment employment all the way through to the harshly demanding environments experienced on missiles, rockets, high altitude aircraft and small satellites where they are greatly needed for their power density. The bottom-line is that to date, nobody has yet understood the nuances required to successfully employ a flat pouch lithium polymer battery system in the harshly demanding environments of the above detailed applications, so their use has thus been contained fully contained within the benign environmental realm of the earth's atmosphere or in similarly protected pressurized vessels such as the space station or within the pressurized and temperature controlled cabin of a spacecraft.
Relatively simple terrestrial-based lithium polymer battery systems presently power countless portable consumer devices (cell phones, PDAs, etc.) for extended hours without recharge, and has enabled a revolution and proliferation of these consumer devices on a mass scale. While it may seem logical that these existing basic lithium polymer systems could be simply adapted for use in the harsh environments/aerospace operational realm for use on small satellites, missiles and rockets, that is not the case. In order to harness and leverage the attributes of the lithium polymer battery into an unprotected and highly demanding aerospace environment, a design, architecture and implementation revolution needed to take place, with this invention being the result of that revolution.
By integrating the requirements of safety, modularity, scalability, expendability, deployability, employability, practicality, radiation hardening and intelligence control into the unprotected operational envelope required of a small satellite, missile, rocket or any high-value vehicle which may be size or weight sensitive and is deployed in a harsh environment, one arrives at this invention which solves the problem of how to provide the world's most dense power source, which is pouch-based lithium polymer for use in the whole spectrum of applications from a benign earth based use, upward, through and into the harsh environment of space.
Current high-tech and heritage aerospace power applications have not yet contemplated the path forward with these flat pouch cell lithium polymer batteries, and are generally still locked into using the older legacy rechargeable battery chemistries such as silver zinc, nickel-cadmium, nickel metal hydride, lithium-ion and lead acid to power their missions. Batteries built using these technologies are routinely heavy and subject to expensive qualification testing and extensive pre-flight checkout in order to ensure their mission readiness as much as possible. These battery systems provide minimal real-time health status feedback, minimal protection and they are not modular or expandable in design. Additionally, with the cost to orbit generally in the $20,000 per pound of weight range, a vehicle is typically 100-300 pounds heavier than it could be if all its batteries were switched to lithium polymer pouch cells. With this switch to lithium polymer batteries alone, approximately 3-9 million dollars of additional payload space and weight could be sold to boost profits or provide additional capability when launched on a missile or rocket system.
Some progress however has been made in the use of non-polymer lithium-ion batteries on aerospace vehicles to deliver far more energy density than other legacy battery systems in a smaller package size. For example, many large satellites successfully utilize straight lithium-ion chemistry very successfully. Contrary to this, the noteworthy press about the 787 Dreamliner's unsuccessful employment of lithium-ion batteries resulted in various aircraft fires that greatly jeopardized safety, and caused extended costly aircraft groundings. To date, the Dreamliner's lithium-ion battery root cause of failure is still not thoroughly understood due to the lack of the ability to monitor each individual cell (their employed brand “Yuasu Cell” has three parallel cells in one canister enclosure, and root cause was not found in that there was no technical insight into the failure mode at the individual cell level). In this Dreamliner scenario, it is well understood that electrolyte leakage of a lithium-ion cell caused an electrical short that lead to battery fire, however the mechanism of how and why it happened is not understood. Subsequent to these fires, and in combination with the lack of full understanding the problem, their design solution was to entomb their lithium-ion batteries in a very fireproof enclosure, and not solve the problem with a robust design as detailed in this invention.
The advanced lithium polymer battery system of this invention in comparison does integrate multiple series and parallel cells, however each individual cell is monitored real-time, and comprehensive protection exists at the cell level. Lithium polymer has very little electrolyte and therefore does not leak liquid electrolyte that can result in a fire, and hence greatly decreases the risk of any battery fire that could be caused by a short circuit from electrolyte leakage such as with baseline lithium-ion technology. Simply put, it is not a safe or acceptable solution for a deployed lithium-ion battery system such as in the Dreamliner to exist where expensive property or human life is at risk. For aircraft carrying passengers, rockets, missiles and satellites, an advanced lithium polymer battery system as detailed in this invention should be employed instead to reduce space, weight, and increase safety.
Given the current state-of-the art ‘either or/or’ situation regarding the choice of using either a heavy legacy battery, a lithium-ion one, or the totally inadaptable consumer grade lithium polymer battery systems such as employed in the remote control model industry, to the best of our knowledge, there is no existing prior art regarding an advanced lithium polymer system as described therein by this patent which can be scaled in size to meet the operational envelope smaller nano/micro satellites and retain the capability to also scale up within its architecture to accommodate even the largest satellites, missiles, rockets or aircraft, or be used without modification of design principles for use in any spectrum of employment from a benign earth based atmosphere, all the way through the harsh environment of space or during transport between the two locations.
While nobody has arrived at a practical, employable and complete integrated solution as detailed by this invention, there are a limited number of inventions addressing broad concepts which are of no help to arrive at the specific intention of this invention. A modular battery pack invention by Hwang et al. only concerns itself with physical battery mounting interfaces for easy modular replacement. The modular control electronics for batteries invented by Ashley et al. only addresses the modular control methods for charging each battery cell to protect the batteries and optimize their performance. Eaves et al. describes an arrangement of two or more cells mounted to a card, with the card or cards then being integrated within an enclosure. With Eaves's arrangement as intended and designed, it is not possible to create a robust structural system that is small enough or light enough to also survive the operational requirements and rigors of a space launch or an orbital environment. Kim's invention only essentially concerns itself with switching out a faulty battery cell via a very complex switching and wiring arrangement, requiring a whopping 10 wires to be attached to each cell in the switching array (in his FIG. 1, note that there are two wires for sensing, two heavy gauge terminal wires and six switching wires around each cell, comprising ten total, which would result in 80 wires required for a nominal eight cell battery) or potentially thousands of wires accumulating into a bundle with the employment of a high voltage large scale battery, and subsequently would be an integrated size/weight packaging nightmare and complexity when the additionally required hardware components such as mosfet switches are integrated. Kim even implies that his approach would be unwieldy to employ on a practical scale in his sixth paragraph under the ‘background’ section of his patent, thus making it impractical for use on an aerospace vehicle, let alone it also complying as a safety critical application. Limbaugh's invention does not attempt to broach the subject of how to design and build a safe and robust power system, however he does mention the need for aerospace platforms to survive intense shock, vibration temperature and acceleration environments, which is all common sense, but offers no hint on how to accomplish this with a lithium polymer battery application. Genin in his pending patent application discusses the importance of an aerospace qualified enclosure mitigating electromagnetic interference, however no reference is made to a design architecture incorporating the capability to manage the real challenge of how one safely and successfully employs lithium polymer batteries in a safety critical environment. Laborde teaches the employment of a data recorder for general aviation aircraft, and the importance of an emergency crash recorder surviving a high-dynamic acceleration crash, however again, no mention about the intricacies of how to design and practically deploy an aerospace application worthy lithium polymer battery system, which requires infinitely more than just crash considerations. Cotton teaches about the importance of monitoring battery parameters (output voltage, impedance, resistance and temperature) via a graphical user interface (GUI) with many batteries in a large-scale backup battery system. FIGS. 1-24 show monitoring output voltage, impedance, resistance and temperature of may battery units via a GUI, but again, neither does Cotton tackle the challenge of working with lithium polymer batteries, and furthermore does not discuss the critical importance of monitoring individual cells real-time (see FIGS. 2 thru 24) contained in the many battery units within a large scale battery system for commercial and/or industrial backup power (see patent paragraph 0003), and as such is not practical for employment in a reduced space and weight harsh aerospace environment, neither is Cotton's complete battery nor are his cells similar in any way to lithium polymer pouch cells or even regular cells. Finally, Hermann primarily discusses the physical arrangement/packaging of battery cells, and only briefly mentions the concept about a Battery Management System in his paragraph 71, but offers no details to even imply he is concerned about the details of how its complexity is administered as detailed in this invention of how we protect, balance and monitor each cell for safety. Additionally, while Hermann mentions a packaging/arrangement concept for his cells, he never goes into the functionality of those cells in that packaging scheme enduring the rigors of a space launch where shock and G levels are so Intense that compression mounting alone will lead to the tearing of a cell pouch, neither does he speak of functionality in orbit where no atmospheric pressure is compressing the cells. Instead, Hermann chooses to only speak about compression plates of sorted designs (spring, foam etc.) to deal with cell expansion and contraction during charge and discharge, and he never mentions the concept of a dynamic slip surface between the cells and his compression structure to eliminate the possibility of tearing a cell pouch. Additionally, while Hermann cites in claim 11 that his ‘battery stack compressible structure’ functions from 60-100 degrees C., his scheme does not accommodate the extreme temperatures of space which range from minus 270 C to plus 120 C.
Due to the nature of these inventions or any currently deployed state-of-the-art systems, none of them can be adapted to even approximate the intent and demands of efficiently designing, integrating, managing and deploying a practical pouch style lithium polymer battery system on smaller satellites or size and weight sensitive missiles or rockets or scaled up architectures of practically any size in any environment from benign earth-based through and into space-based for the following reasons:
(a) There is no practical system or architecture available to provide miniaturized real-time monitoring/feedback of multiple arrays of deployed lithium polymer batteries to enable instant determination of their individual cell safety critical parameters (voltage, current, state of charge, state of health, and temperature) during readiness for flight or flight itself.(b) Rapid and efficient lithium polymer battery cell conditioning and balancing is not possible within the architecture of these prior art inventions or any employed systems if employed on a satellite or launch vehicle.(c) No capability exists for real-time data gathering from all lithium polymer cells comprising a battery which could be used on a small satellite or weight sensitive launch vehicle, and if it did in accordance with existing architectures, it would require large accumulating bundles of wires as the number of cells grew past just a handful.(d) It is not possible to efficiently protect any existing lithium polymer battery system from an over charge, under voltage and short circuit situation on an individual cell basis if the number of cells and subsequent battery size is a large and complex matrix expansion, nor is this large matrix expansion adaptable for use on smaller nano/micro satellites or weight sensitive launching systems.(e) No efficient and deployable fail-over/safe system exists to ensure functionality if a single lithium polymer cell fails within a battery being attempted for use on a small satellite or any mission and safety critical aerospace vehicle.(f) All present battery system designs negate their practical adaption for use with lithium polymer chemistry, nor are they practical or deployable in any manner in a standard configuration or an efficient modular ‘Lego’ system architecture, either in a physical arrangement or electrical one.(g) The limited design flexibility of existing deployed aerospace battery systems make them inadaptable to lithium polymer chemistry, and thus precludes the possibility of their integration with a real-time battery management system that could take advantage of the increased characteristics that could be demonstrated of this were possible.(h) Present practical battery design configurations are limited to their individual unique manufacture, and do not allow for their physical or electronic adaptation into lithium polymer chemistry for use on small satellites or weight sensitive launch vehicles.(i) Existing deployed battery systems are not adaptable to small satellites or weight sensitive launch vehicles, and therefore do not incorporate methodology for isolating/combining battery strings via software command in the event that mission requirements change real-time, or if a battery has an internal failure.(j) All of today's battery systems for aerospace use are based upon older technologies or rely on large satellites to carry them, and are size/weight excessive in addition to being very inefficient in architecture when compared to the advanced lithium polymer system of this invention.(k) In addition to power density and unwieldy architecture problems that accompany the limiting factors encountered in fielding older battery technology or proposed lithium polymer technology, these approaches suffer from significant operations and maintenance issues and costs related to access, recondition and service the batteries, especially if they are being considered for use on small satellites.(l) Thermal packaging issues presently plague all aerospace battery designs due to their inefficient systems architecture and higher cell internal resistance compared to Lithium polymer implementation, with no cost effective way to circumvent them due to their size and non-scalability for use on smaller, more efficient vehicles.(m) Launch environments are presently extreme to standard battery systems that are flown, and cause labor intensive and costly pre-qualification testing methods to be employed to mitigate potential problems from surfacing during the operational employment of these existing systems.(n) Size and weight issues constantly arise during consideration of, or employment of existing battery systems, resulting in the sacrifice of other mission capabilities.(o) Current aerospace application battery systems are limited by the arrangement of cells and their large amount of individual wiring to develop a particular battery voltage and capacity, and are not easily reconfigured in the event of a change in mission rules or application requiring a change in voltage or current capacity, nor are their designs applicable for packaging lithium polymer pouch cells where the battery thickness increases during charge and decreasing during discharge. Also, the pouch cell material will tear under extreme high shock (1000 s of Gs) and vibration (30-100 GRMS) without a dynamic packaging mechanism that is included in this invention.(p) Fielded aerospace battery systems, lithium polymer or not, are incapable of providing a practical deployable method to instantaneously monitor individual cells on a practical real-time basis, predicting a battery cell failure with a battery prognostic algorithm by monitoring each cell performance during charge and discharge, and thus precluding the capability to notice and avoid a battery cell failure before it happens, whether in a small or larger scale battery.(q) Today's battery systems do not employ an efficient and deployable architecture for use on smaller satellites or weight sensitive launch vehicles to enable the capability for predictive performance in accordance with the number of cycles it has been subject to.(r) Present battery architectures do not allow for a larger method of control aside from the immediate system they are employed within, thus eliminating the possibility of mesh network control in a swarm of small satellites, and an efficient redundant power switching employment.(s) No lithium polymer battery systems exist today that can function and be monitored real-time down to the cell level in the severely demanding environments of missile/rocket launch or space.(t) Existing battery systems cannot be scaled from small to large in a practical way that maintains simplicity of integration and operation.(u) Deployed battery systems do not have the capability to rapidly and fully recharge within the approximate 45-minute timeframe of a low earth orbit in the sun from a fifty percent depth of discharge.(v) Existing terrestrial employments of pouch style lithium polymer systems will not work in the vacuum of space without proper thermal packaging.(w) No pouch-style lithium polymer system to date can monitor individual cell parameters in real-time.(x) There are no pouch-style lithium polymer battery systems that are dynamically packaged to survive the rigors of space-launch (extreme shock, vibration and electromagnetic interference), and the harsh environments of space (thermal cycle, vacuum and radiation).(y) Present pouch-style lithium polymer applications do not employ a method for accommodating the expansion and contraction of multiple stacked cells during battery charge and discharge due to the benign environments they always operate in.(z) Presently employed pouch-style lithium polymer systems have never developed an interface for remote cell monitoring via a telemetry system.